Age and Gender will be populated by using DOB and sex columnsSee the example...

CREATE TABLE testCase
(
id int,
name varchar(10),
DOB date,
sex int,
age as case when DATEDIFF(YY,DOB, getDate()) between 50 and 100 then 'Senior Citizen' Else 'Unknown' End,
Gender as case when Sex = 1 then 'M' Else 'F' End
)
--Observe this. you are NOT providing data for age and Gender columns
insert into testCase(id, name, DOB, sex) values(1, 'aaa', '1953-10-27', 2)
--Here you can see data for age and Gender columns
SELECT * FROM testCase